English verb conjugation
CAN CURTAIN

Regular verb: curtain - curtained - curtained

Affirmation

Simple form	V-ing form
I can curtain you can curtain he can curtain we can curtain you can curtain they can curtain	I can be curtaining you can be curtaining he can be curtaining we can be curtaining you can be curtaining they can be curtaining
Perfect	V-ing perfect
I can have curtained you can have curtained he can have curtained we can have curtained you can have curtained they can have curtained	I can have been curtaining you can have been curtaining he can have been curtaining we can have been curtaining you can have been curtaining they can have been curtaining

Negation

Simple form	V-ing form
I can't curtain you can't curtain he can't curtain we can't curtain you can't curtain they can't curtain	I can't be curtaining you can't be curtaining he can't be curtaining we can't be curtaining you can't be curtaining they can't be curtaining
Perfect	V-ing perfect
I can't have curtained you can't have curtained he can't have curtained we can't have curtained you can't have curtained they can't have curtained	I can't have been curtaining you can't have been curtaining he can't have been curtaining we can't have been curtaining you can't have been curtaining they can't have been curtaining

Interrogative form

Simple form	V-ing form
can I curtain? can you curtain? can he curtain? can we curtain? can you curtain? can they curtain?	can I be curtaining? can you be curtaining? can he be curtaining? can we be curtaining? can you be curtaining? can they be curtaining?
Perfect	V-ing perfect
can I have curtained? can you have curtained? can he have curtained? can we have curtained? can you have curtained? can they have curtained?	can I have been curtaining? can you have been curtaining? can he have been curtaining? can we have been curtaining? can you have been curtaining? can they have been curtaining?

Interro-negative form

Simple form	V-ing form
can't I curtain? can't you curtain? can't he curtain? can't we curtain? can't you curtain? can't they curtain?	can't I be curtaining? can't you be curtaining? can't he be curtaining? can't we be curtaining? can't you be curtaining? can't they be curtaining?
Perfect	V-ing perfect
can't I have curtained? can't you have curtained? can't he have curtained? can't we have curtained? can't you have curtained? can't they have curtained?	can't I have been curtaining? can't you have been curtaining? can't he have been curtaining? can't we have been curtaining? can't you have been curtaining? can't they have been curtaining?